I have mixed feelings on this. I'm siding with the devs that it doesn't make much sense to continue supporting an aging architecture. However, at the same time, there are still quite a few 32-bit apps out there that will no longer work on the latest version of Ubuntu and derivatives. The nice thing is, that it's not removing support on any existing builds, so it will be possible to continue running that specific version of Ubuntu while we wait for the devs of Steam to build a compatible 64-bit client. So, in a way I don't see this as being the end of gaming on Linux, but rather a bump that they're going to have to jump over if they want to continue supporting the platform. Considering how much work has gone into the project including Proton, I don't think Valve is going to throw it all out. I honestly believe they will develop a 64-bit version of Steam and then all will be well again. Maybe, if it comes down to it, create some kind of wrapper for those games that are only 32-bit so that they are still able to run.